Challenging Perineural Invasion Case

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1K Member
15+ Year Member
Jul 6, 2004
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We've been getting a few cases of perineural invasion from skin cancers over the past few months. I had a question about one such guy I recently saw

71 yo man with a distant history of resected skin cancers now presented with 3 months of worsening facial numbness in maxillary trigeminal distribution (V2). MRI showed V2 nerve enhancement extending from Meckel's cave to foramen rotundum concerning for perinerual invasion. No visual sxs. Had a right cheek melanoma 8 years ago completely resected no PNI, no adjuvant tx recommended and a left neck melanoma with negative neck dissection 10 years ago. Otherwise no significant skin history, not a guy with much in the way of sun spots/skin irregularities. ENT attempted biopsy of right infraorbital nerve and a benign looking lesion on the right cheek all negative.

Just curious if people have thoughts. What further wkup would you do (anything that can mimic this type of situation)? What RT dose/fractionation would you consider, what to cover and constraints to consider. Concurrent chemo? Appreciate the thoughts


Full Member
7+ Year Member
Aug 13, 2011
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We had a similar case with a patient with progressive numbness in V1 distribution along with CN3 palsy. Very subtle enhancement along V1 and CN3 on MRI. Remote history of non-melanoma skin scc without any prior lesions clearly lying in a V1 distribution. After much wringing of hands (and an ophtho consult to rule out other etiologies), we ended up treating empirically to 5940 in 33 fx to the entire length of V1 to skin and affected portion of CN3, respecting ON dose constraints, no chemo.

Your case actually sounds more compelling for empiric treatment given the history of right cheek lesion, albeit remote. Good luck getting a med onc to give chemo in the absence of tissue diagnosis.


Full Member
5+ Year Member
Jun 25, 2016
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Almost no data for chemo in these cases except one article from UNC, (NCCN guidelines -if I recall -once said to consider it based on head and neck cancer treatment principles) nevertheless, I always push for it when skin cancer are aggressive like this or met to lymph nodes.